CHON particles

CHON particles

Dust particles that were discovered in the coma of Halley's comet during the Giotto mission and were found to consist mainly of the light elements carbon, hydrogen, oxygen, and nitrogen and thus of a distinct compositional type. They are thought to be snowflakes that were being blown away from the cometary nucleus and would be short-lived.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006